Would is, of course, the conditional form of will. It’s used to express a potential (or non-existent) rather than a certain future state of being.

So it’s I will have the memo for you today but I would like to give you the memo today, but I’ve been asked to work on a big due diligence project instead.

Relatively straightforward, one would think – but one would be wrong.

Tense accord
No, not a strained agreement, but the proper alignment of various verb tenses.

I would be a rich man if I had a dollar for every time I’ve seen something like this:

I would have started on your memo earlier if I would have known that the big due diligence project was about to land on me.

Wrong, so wrong. That second would have needs to be had.

Getting technical with talk of the pluperfect and the conditional perfect (aka past conditional) is likely to confuse, so just remember that it’s never correct to have two would have (or similar) constructions in succession like this.

Journalistic conditional
Happily there isn’t too much of this in legal writing, but open the newspapers and it abounds (especially in the obituaries). By way of example (emphasis added):

‘Steven breathed a rich mixture of political gossip (he would go on to meet all but three of the 20th century’s Prime Ministers).’

That would go should just be a simple went (or just say he later met all but three…).

Would of
Ugh. But I certainly hear and sometimes even see would of.

In spoken English, would have can sound like the contracted form would’ve, which has led some astray into thinking that it’s actually would of.